I'm getting my winter tires put on my grey turbines (and getting some road rash refurbished on a couple of wheels) and went back to the 19" slipstreams for a week - what a difference in ride quality! The noise went from very little to almost none but the main difference is this additional cushion of air you just glide on with the 19"'s. It seems like this car was meant to be driven on the smaller tires but I just can't quit those gorgeous turbines! I'm really going to enjoy this week. Anyone else switch back and forth between the different sizes and notice this drastic difference?